As a follow-up to this thread I was counting the number of women riding in the morning, and there was a total of 4 out of probably 50-100 riders that I saw on my ride. It really did change, either with the weather or with the darkness. In the summer it is more like 60-40 men to women, so while not even, not that skewed towards men. On the way home I only saw one woman, and she was riding with somebody and didn't look like a commuter.

And as an aside, I was far and away the oldest commuter on the road at 57. Maybe someone was older, but I doubt it.